Some examples of modern distributed computing systems include networked computers, net servers, and larger enterprise systems. These and other distributed computing systems often involve databases that contain bundles of textual data, which can be thought of and referred to as “documents,” and which may be indexed and queried.
A distributed index and query system processes incoming documents to create a searchable index while at the same time processing queries on the index or indexes and documents indexed therein. In a resource constrained environment, the index and query tasks compete for system resources such as: network throughput, bus bandwidth, memory, disk speed, various cache sizes, and processor usage. Interaction between the index and query tasks as they compete for resources is difficult to model as implementations of a system and the hardware on which it runs are often not identical or may be subject to frequent change. Contention between resources and/or problems in scheduling index and query tasks results in poor performance of the system. Poor performance may be evidenced by a slowdown in indexing new documents, a slowdown in querying response times, or a slowdown of both tasks.